[ 4 5 & 3 
of heat, may a (lid; us in difcovering thofe which are 
produced upon our bodies from the fame caufe. 
104. The point o of my. hygrometer, as I have 
before obferved (44), is that of the extreme humi- 
dity produced by melting ice. It was therefore of 
fame importance to know what difference there 
would be in this point, when the hygrometer lhould 
be plunged into warmer water. This I endeavoured 
to find out ; and the following is the refult of my 
;fii\ft inquiries. 
105. The moment I took one of my hygro- 
meters out of melting ice, I plunged it into water at 
• the heat of 45 degrees of the thermometer that I 
have called common. It fell fuddenlv four of its de- 
* 
grees below the thread which marked its height in 
the melting ice, but immediately rofe again, and in 
four minutes reached 8 decrees and a half above the 
fame thread. Deducting 22 \ from the height for 
the dilatation of the mercury (48), there will remain 
14. Confequently the water warmed at 45 degrees 
of the common thermometer, really made the hy- 
grometer fink 14 degrees below o. 
106. Half an hour after this, the water being at 38 
degrees, I found the hygrometer no .higher than 6 f, 
that is to fay, 6f — — — — 12T Confequently 
the true point of humidity indicated by the hygro- 
meter was 1 2f below o. Laftly, the heat of the 
water being reduced to 28 degrees the hvgrometer 
was at 3 — ~ — — ir. I was then obliged to put 
an end to the experiment, which I have not been able 
t_o take up again fince, for .want of leiiure. But 
j what 
